i were told the same thing redline. but, i has turned out to be the least true of many things untrue things that i have been told in this hobby. i have quite a few of them in my tank. i have probaly had less trouble out of them than anything i've had. the guy at my old lfs swears that they kill the fish when there asleep! even being a newbie i found that hard to believe. like a fish is going to set still and let a little worm knaw it to death. i'm like, wouldn't the fish just swim away if something trying to eat it? and he said oh no, they are fish killers. then he swears he's never had any in his tanks! yeah right. the first piece of live rock i bought came from his display tank. got it home and pulled it out of the box and three bristleworms were laying in the bottom. but anyway, what i started to say three paragraphs ago is that good advice is hard to find....except in here!